Lean and Flexible Manufacturing

Starting out with a clean slate, the Global Engine Manufacturing Alliance (GEMA, Dundee, MI), a joint venture between DaimlerChrysler Corp., Hyundai Motor Co., and Mitsubishi Motors Corp., has forged an engine manufacturing operation built on lean principles, with United Auto Workers (UAW) employees embracing more flexible work hours and rules, and an agile, flexible plant design promising to bring large volumes of more powerful, fuel-efficient four-cylinder engines to its three partner companies worldwide.

Ramping up its second plant in October, the 275-acre GEMA facility plans to eventually build 840,000 engines annually at the Dundee site, which is part of GEMA's five-factory global engine-building alliance. After starting production in October 2005, the GEMA North plant in Dundee now builds about 420,000 engines a year, and when the venture opens its South plant next month, the $803-million facility will have approximately 900,000 ft2 (83,700 m2) of total manufacturing floor space to reach its full production capacity.

The GEMA World Engine family of four-cylinder engines includes 1.8, 2.0, and 2.4-liter DOHC versions, plus a high-output 300-hp 2.4-liter DOHC Turbo that will be produced for each of the joint venture partners. The initial base engine design for the World Engine family came from Hyundai, and the partners are introducing powerplants featuring codeveloped model variations, including advanced features such as dual variable-valve timing and other attributes typically found on more expensive luxury vehicles. DaimlerChrysler's Chrysler Group is using the World Engine in its Dodge Caliber and Jeep Compass models. The engine design is also built by Hyundai at plants in Asan and Hwasung, South Korea, and by Mitsubishi in Shiga, Japan, for a total worldwide manufacturing capacity of about 1.8 million units.

To build with a lean philosophy, GEMA first extensively benchmarked manufacturing processes, products, and organizations, according to Bruce D. Coventry, GEMA president. "We wanted to build the entire foundation on lean, so we did a lot of benchmarking. We looked at a number of different organizations, people, and processes, and we looked at the product itself," Coventry says. "With the Korean and Japanese partners, we obviously looked at something like the Shingo Prize metrics as a starting point, and we spent a lot of time looking at enablers, cooperation, and results.

"When we first started the program, there were three core processes that we wanted to build the organization around," Coventry adds. "One was innovation; we wanted to be very different and cutting-edge, leading-edge, in what we were doing. The other thing is, we wanted to really pay attention to our focus, and that really gets us to what adds value to the customer."

After extensive analysis, GEMA outsourced many key operations—maintenance, material handling, tool sharpening/cutter grinding, and even final engine dress—with the goal of focusing on value-added tasks such as precision machining operations. "Even some of the core components for the engine that historically had been done by engine plants, we challenged and said, 'maybe we get a better outcome elsewhere,' so we subjected all of our main components to a make-buy analysis," Coventry notes. "We're only producing three parts of the more than 215 part numbers that go into the engine—the cylinder block, the cylinder head, and the crankshaft."

Producing cylinder blocks, cylinder heads, and crankshafts, the '3C' operation at GEMA's Dundee site varies from the typical model for automotive engine building, where engine plants that are often called 5C plants usually produce those three major engine components, plus connecting rods, camshafts, pistons, and intake/exhaust manifolds, along with performing final assembly, or final dress, of those pieces at the same facility. At the Dundee site, those operations are outsourced to its partner, Android Industries (Auburn Hills, MI), which assembles the final dressed engine with all components after receiving the long block assembly from GEMA. "Certainly a lot of the other components that would be typically done at an engine plant—connecting rods, camshaft, pistons, intake/exhaust manifold—all of those were subjected to make/buy, and we found a better deal," Coventry adds.

Flexibility and agility in both people and process has enabled GEMA to build an operation based on lean principles right from its start-up in April 2003, when the operation broke ground for the Dundee facility. With union workers, GEMA has a single job classification where team members are empowered to do any job necessary under the philosophy of 4A (Anyone, Anytime, Anywhere, Anything) that forms a key building block of the GEMA Production System (GPS). Under the 4A concept, each employee is a team member who contributes, crews rotate work schedules, team members rotate through machining and assembly operations, and cross-training ensures that team members have the requisite knowledge and skills to do the job.

At Dundee, GEMA's work contract offers flexibility for both the company and workers. The facility's team members work a 3/2/120 schedule, consisting of three rotating crews working two shifts of 10-hr days with no overtime. The innovative scheduling allows employees to get 49 extra days off per year, while the plant runs six days a week without overtime for 49 more days of operation than a typical plant. The facility's workers are highly skilled, with GEMA requiring new workers to have either a two-year technical degree, a skilled-trade journeyman's card, or five-years experience in CNC machining, and many employees work on finishing degrees at the plant's on-site training facilities with courses from the University of Toledo.

The plant's work schedule in part enables GEMA to run lights-out in assembly, as well as in the facility's highly automated machining operations, and flexibility in people, product, and process will allow the GEMA plant to quickly adapt to fluctuating market demand. "It's really more the process flexibility, but all three—people, product, and process—give us a great deal of flexibility," Coventry says. "With the product itself, it's a family of four-cylinder engines, but we have so much machining flexibility that we could produce many different derivatives. We could produce direct injection, hybrid—there's a lot of different variants that we could produce with the flexibility that we have.

"The most important factor in terms of flexibility is really our people. The ability to have a single job classification that allows our employees to virtually work on operations anywhere in the plant. We had the ability to negotiate an all-new contract, because we were an all-new company. But on the other hand, it really shows the competitiveness of the UAW, to participate in this type of a process. We have a very productive relationship with the UAW, and they're full partners in our process."

At full volume, GEMA expects to have about 250 team members and about 150 salaried employees. Training includes an initial orientation of four weeks in the classroom, transitioning over to on-the-job training on the manufacturing floor. Basic technical training in specific job-related areas can go to 500 hr, with some advanced areas like controls and robotics reaching 800 hr.

"In terms of lean, we recognize our competition and we have manned the facility very aggressively, so our intent is that this would be among the leanest facilities in the industry," Coventry says. "We have a production system, we call it GPS, that sort of guides our way. GPS is really the general production system, but it would reflect many of the characteristics of the Toyota Production System. I think one of the big differentiators between Toyota's process, and their people and ours, is that we tend to have a higher skill level; I would say the one differentiator that we have sought, right from the very beginning, would be to have higher skills."

With its precision-machining focus, GEMA lowered its fixed costs by outsourcing final engine dress to Android Industries, which receives a long block engine from GEMA and performs the final dress of the engines, which are then shipped in sequence as full assemblies to automotive OEM plants. The Dundee plant currently sends engines to Android for the DaimlerChrysler's Belvidere, IL, factory that builds the new 2007 Dodge Caliber, and it will be working similarly with Chrysler Group's Sterling Heights, MI, assembly plant.

"In our business case, we want to be very good at the high-precision areas, the ones that add value to the customer and really determine the overall quality, durability, and performance of the engine," Coventry states, "and that all gets down to the precision machining of our components. We want to be very good, and very focused, on providing the highest quality base engine that we possibly can. The rest of the components are bolt-on, and the requirements are not as high."

The process includes GEMA engines shipped to its third-party supplier along with other engine components, such as manifolds and pumps, and transmissions. "This is how the process flow works," Coventry says.

"GEMA produces essentially what we would call a long-block engine, and we ship that engine to our third-party supplier. There are transmissions, in this particular case, automatic and manual, and those components get shipped into the third-party module supplier. The parts are integrated into a powertrain module, which is then shipped in sequence, just-in-time, to the assembly plant customer. In this case, this path is 6.5 min, from the end of the line at Android right across the street to the load of the vehicle line at Belvidere—and that works just like clockwork."

On the factory floor, the GEMA Dundee facility currently has about 594 machines deployed in highly flexible machining cells. "In general, we've tried to make the size of our increments smaller," Coventry says. "In a transfer-line process, an efficient increment is usually 400,000-500,000 units a year, and what we've tried to do is get our line increments down much smaller. So if you look at the A line and the B line within each of our operations out there today, you'll see each one of those represents about 210,000 units of capacity. They're all CNC so they're highly flexible, and then those are married together, generally with overhead gantries, that allow autonomy within each of the individual machines, so we get much higher utilization rates, much higher uptime, and much higher throughputs."

The cylinder block lines use predominantly CNC machines from Mitsubishi Heavy Industries, while the cylinder head lines have equipment from Nippei Toyama. "On the crankshaft line, the rough end is predominantly Japanese CNC, from a variety of different manufacturers," Coventry adds, "and the finish end, the grind line, is pretty much Landis. Our stated capacity is 840,000 units a year, and with our line rates right now, with two shifts running, we're up over 1600 a day, so we're very closely approaching our daily capacity, and as our schedules continue to ramp up, we'll get there very quickly."

Some of the systems use on-machine metrology, with machining on the crankshaft and cylinder-head lines using some closed-loop-feedback systems on the machines, he adds. "We also do in-process 100% inspection of critical characteristics, and we have a very aggressive CMM lab approach that allows us to determine streams of variability, and we will control process based on the data and the feedback that comes from our metrology. And of course, we have the actual process control, frequency-based dimensional control plan.

"The thing that's different about our process is that in a transfer line, you have the single source of machining" you know exactly where the part came from. In our process, we have operations, for example, the Op 60 in the head line has 14 identical machines doing the same operation. If you've got an issue on a part, what machine did it come from? Traceability becomes very important. Process control becomes very important.

"Trying to run a process on lean becomes much more important, and knowing exactly what the process behavior characteristics are is essential for us to be able to control the quality of the parts we are producing. Many of the tolerances that we're holding out here are much more precise—we hold tolerances down to three microns, four microns, in that range. We have a number of tolerances in the plant that are that tight."

Tight tolerances are critical, especially for components such as the crankshaft journal, due to the widespread use of select-fit components throughout the World Engine. "One of the aspects of the design itself is that 40% of the parts that go into this engine are select fit," Coventry notes. "By part number, this engine has more select-fit components than any engine produced in any of the three companies, DaimlerChrysler, Hyundai, and Mitsubishi.

"What we're doing [with select fit] is we're matching either by size or by weight to achieve an optimum clearance, in order to achieve an optimum balance," Coventry adds. "For example, every rod in the engine was selected within three grams, so the reciprocating, rotating mass of the engine is all the same; you don't have one piston going up at a different mass than another, giving you excessive vibration. Our bearing clearances are controlled very precisely so that from a noise, vibration, and harshness [NVH] standpoint, you've got very, very good control."

Out in the shop, visitors to GEMA's Dundee facility see that the North and South plants are mirror images of each other, with both under the same roof, notes Frank S. Lo Scrudato, GEMA staff engineering manager, service partners. In machining, the CNC equipment can run untended, lights-out for long stretches without operator intervention.

"All of this equipment will go 20 hours without a shutdown," Lo Scrudato says. "These are standard CNC machines, again another advantage of the bundling—they're the same CNC machines that our partners have, and this is an example of our parallel-process architecture. These machines are all in parallel—they're doing the exact same work from machine-to-machine. Each machine has the same tools."

Machining cell status can be easily monitored on Andon boards with color-coded green-yellow-red lights indicating each machine's progress, so team members quickly determine whether a system needs attention. "The Andon board is the principal way for our people to communicate on what's needed on the production line," Lo Scrudato notes.

Another lean tool employed is a basic production board by which workers track manufacturing progress. "It has to do with a lean environment—you want to do what you need to do and you don't want to make things overburdening," he adds. "You want to give the workforce what they need to do the job, and what they need to manage the business. It's not only key for GEMA's future, but it's a key for manufacturing in Michigan and the United States.

"We looked at lean manufacturing, all the theories and concepts, and we selected the ones that we knew would be valuable to us and a key to our future. We incorporated and we innovated new things like the 4A concept, and we trained the people—and that's the most important thing. It's not only important to havea GPS system, but it's important to get the message out and create the culture."

On the cylinder head line, four cells, each with 14 CNC multifunction machines from Nippei Toyoma Corp. (NTC, Japan), perform milling, reaming, tapping, boring, and high-speed drilling operations, using a combination of polycrystalline diamond (PCD), cubic boron nitride (CBN), and carbide tools. "This cell right here, this Op 60 cell, is one of the largest," notes Lo Scrudato. "This is another example of where we're looking at flexibility. Flexibility to us has a lot to do with being able to produce multiple models in the same shop, and be able to adjust to customer demand, so we are using this adapter plate here—as long as we don't change the features or the bolthole pattern and the manufacturing holes on the exhaust face, we can make a different cylinder head.

"We have four slots open in CNC machines; things can be added, things can be changed, we can make a different model cylinder head if we need to. That was important to us when we laid out this process, because we want to be product-flexible, but also these processes give us process agility. If we need to make processes improvements, continuous-improvement items, changes can be made very easily on a CNC machine."

Concentrating on its core business, GEMA also makes extensive use of cubing and super-cubing with its cylinder head casting supplier, Nemak, delivering cast components that need less machining time and that are pretested for porosity, he adds. "Our core business is making engines, and these three components are critical to the engine, so we're using cubing and super-cubing processes with our casting suppliers in order to concentrate purely on the features that are really adding value and functionality to the cylinder head."

For traceability, each cylinder head gets a unique number, a combination of the date, tools used, the line it's produced on, and a serial number that is stamped on the components with a 2-D matrix similar to a UPS bar code, as well as a human-readable code.

Tool management is outsourced to GEMA's tool-management partner, Mahar, which uses a Remstar automated tool storage and retrieval system, and the factory is charged only for the time tools are used. Next to the Remstar system, in a climate-controlled presetting room, the company uses Zoller presetting machines with shrink-fit tooling from a variety of suppliers to precisely preset all tools.

In the metrology room, GEMA has three Zeiss CMMs for checking components requiring the highest-possible precision. "This is fundamental, and here is where we set the bar, a hospital-clean environment," Lo Scrudato states. "Cleanliness in an engine is extremely important. We use these to do audit checks, and to define some of our process capabilities. The accuracy on these machines allows us to inspect the features that we have, in the cylinder head and block principally, where we're getting into that micron range of inspection."

The plant uses Adcole inspection systems for checking quality of crankshafts and camshafts, he adds. "These are very common in the industry. They provide extreme accuracy for inspecting a crankshaft or a camshaft, and we use them to check some of those micron/submicron characteristics that we have on the crankshaft," Lo Scrudato notes. "We don't make the camshaft here, but we may do an inspection. Here, we use the full in-process inspection, and also check some of our in-process characteristics. Again, controlling the inputs, we don't wait till the crankshaft is finished to control some of the forms and some of the very micron/submicron characteristics—we check those in-process.

This article was first published in the September 2006 edition of Manufacturing Engineering magazine.